I'm watching Sanders, and I think he's been his usual dynamic self. However, I don't think he's done much of anything to try to appeal beyond his base. This of course has been a long-standing issue with Sanders. Now, if the field remains very fragmented, maybe it doesn't matter -- he can win with a plurality. But I think in the face of Buttigieg's improvement, Sanders would be in a stronger position in New Hampshire if he were pulling in other voters (even if they're other left-leaning supporters of Warren). That would improve his chances. I'm not sure he's capable of broadening his appeal, though.